Researchers from Greece presented hopeful findings this week in the fight against drug-resistant bacteria superbugs at the Society for General Microbiology’s spring meeting. Essential oils could be a cheap and effective alternative to antibiotics.

Researchers from the Technological Educational Institute of Ionian Islands tested the antimicrobial activity of eight plant essential oils. They found that the oils of thyme and cinnamon were particularly effective against a range of Staphylococcus species. In fact, thyme oil was the most effective essential oil tested, able to almost completely eliminate bacteria within 60 minutes.

“Not only are essential oils a cheap and effective treatment option for antibiotic-resistant strains, but decreased use of antibiotics will help minimize the risk of new strains of antibiotic resistant micro-organisms emerging,” said Professor Yiannis Samaras, one of the study authors. “The oils – or their active ingredients – could easily be incorporated into antimicrobial creams or gels for external application.” The researchers also proposed that the oils could be used in food packaging to replace synthetic chemical preservatives.

Essential oils are aromatic oily liquids obtained from plant materials, including flowers, buds, seeds, leaves, and roots. There are about 3000 known and have been used for hundreds of years for their therapeutic properties. Australian aborigines, for example, have used tea tree oil to treat colds, sore throats, skin infections and insect bites.

In 2006, Indian researchers published a study in the BMC Complementary and Alternative Medicine Journal that evaluated the antibacterial activity of 21 plant essential oils against six bacterial species. Nineteen of those showed positive results against one or more strains. These researchers also found cinnamon oil to be very promising even at low concentrations. Other essential oils with positive results included clove, geranium, lemon, lime, orange, and rosemary oils. Those least effective were aniseed, eucalyptus, and camphor oils.

Thyme oil is a reddish-brown/amber-colored oil that is extracted from the fresh or partly dried flowering tops and leaves of the evergreen thyme shrub. One potential downside to using this oil in anti-microbial creams is that its phenolic properties can irritate mucus membranes and cause skin irritation.

Cinnamon oil, when applied topically, is generally safe, but can cause allergic reaction in some. A product called “Thieves Oil”, a combination of cinnamon bark, clove, lemon, eucalyptus and rosemary, was studied in 1997 by researchers at Weber State University and found to have positive results against multiple bacteria after only 10 minutes of exposure. Dr. Lawrence Rosen MD, a pediatrician who has been featured in the New York Times and on NBC News, has offered a “recipe” for a home-made essential oil hand sanitizer featuring cinnamon oil.